Last year, it was announced that The Big Bang Theory, the long-running CBS sitcom that’s currently one of the world’s most popular, would soon be coming to an end, with its 12th and final season due in 2019.

But as much as fans might be saddened by CBS’s decision, nobody can say the show hasn’t had one hell of a run.

Having first begun airing in 2007, The Big Bang Theory has since gone on to become one of the most successful US sitcoms ever.

Not only do millions of viewers regularly tune in, but the show has won and been nominated for dozens of awards in its time, with ten Emmys and one Golden Globe to its name.

As the show gets ready to wrap up for good, here are ten things you never knew about The Big Bang Theory.

25. The original, rejected pilot for the show featured entirely different characters

Unusually, when Chuck Lorre was shopping The Big Bang Theory around between 2006 and 2007, he produced not one but two pilots.

[rtk_adunit_top]

The original pilot, produced in 2006, featured the familiar characters of Leonard and Sheldon, as played by Johnny Galecki and Jim Parsons, but otherwise had an entirely different set of characters.

These included two female leads: “tough-as-nails” Katie along with Leonard and Sheldon’s fellow scientist Gilda, respectively played by Amanda Walsh and Iris Bahr.

This pilot was rejected after poor test audience results, but Lorre was given a second chance: he retooled his next pilot by retaining Galecki and Parsons and introducing Penny, Howard and Raj actors Kaley Cuoco, Simon Helberg and Kunal Nayyar.

[rtk_adunit_middle]

24. Jim Parsons originally thought he was auditioning for a game show

Though he was responsible for some of the biggest sitcoms of the day – Two and a Half Men, Dharma & Greg – Jim Parsons had never heard of Big Bang creator Chuck Lorre back in 2006.

[rtk_adunit_bottom]

This is why, when he was offered the Big Bang pilot, Parsons felt so underwhelmed – he confused Chuck Lorre with game show host Chuck Woolery.

In 2014, Parsons told David Letterman: “I thought, why are they so excited about it? We should see what the man has to offer before we’re like, ‘It’s a new Chuck Woolery pilot!'”

[rtk_adunit_top]

23. Wil Wheaton got his role through Twitter

Best known to a certain generation as the young star of Stand by Me and Star Trek: The Next Generation, Big Bang might be the project actor Wil Wheaton is best known for these days.

[rtk_adunit_middle]

And to think, the role he plays on the show – a sinister version of himself – only came about as a result of a throwaway comment on Twitter.

In 2014, Wheaton told Larry King he “was talking on Twitter about how much I loved the show” when both executive producer Steven Molaro and Big Bang co-creator Bill Prady got in touch offering a part.

Wheaton has since become one of the show’s semi-regulars.

[rtk_adunit_bottom]

22. Nobody knows Penny’s last name

It’s been 11-and-a-half seasons and, as yet, still nobody knows Penny’s last name (at least, the one she had before she married Leonard).

[rtk_adunit_top]

It’s possible the mystery will be solved in the currently-airing final season, but don’t hold your breath.

In 2014, Steven Molaro told Vulture: “We’re kind of a superstitious lot here. We’ve made it this far without knowing Penny’s last name. I think we’re good not finding out.”

[rtk_adunit_middle]

21. A Belarus TV network copied Big Bang without permission

At the end of the season 3 episode The Large Hadron Collision, Chuck Lorre included one of his trademark vanity cards – though this one was slightly different.

[rtk_adunit_bottom]

Vanity card #277 detailed a case of plagiarism: a Belarus TV network had created a Belorussian carbon copy of Big Bang – complete with characters named Sheldon, Leo, Hovard, Raj and Natasha – called The Theorists.

According to the card, no legal action could be taken as “it’s next to impossible to sue for copyright infringement in Belarus because the TV production company that is ripping us off is owned and operated by the government of Belarus.”

The Theorists was soon cancelled regardless.

[rtk_adunit_top]

20. Numbers in the show carry secret meanings

Big Bang is awash with in-jokes, none-more-so than where recurring numbers are concerned.

[rtk_adunit_middle]

In the show, Sheldon’s favourite number – which appears on his clothing from time to time – is 73. This is in reference to the year Jim Parsons was born, 1973.

Apartment numbers also carry a hidden meaning: Amy Farrah Fowler’s, 314, is the first three digits of pi, while Wil Wheaton’s, 1701, refers to then hull number of the USS Enterprise, from the Wheaton-starring Star Trek: The Next Generation.

[rtk_adunit_bottom]

19. Mayim Bialik really has a PhD in neuroscience

Mayim Bialik might not be much like her Big Bang character in real life, but the two do share one thing: they both have a PhD in neuroscience.

[rtk_adunit_top]

In fact, Amy Farrah Fowler was rewritten as a neuroscientist because of Bialik’s casting, with Bialik telling Variety in 2015 that producers “didn’t have a profession for my character when I came on in the finale of season 3.”

According to Bialik, “Bill Prady said they’d make her what I am so I could fix things (in the script) if they were wrong.”

[rtk_adunit_middle]

18. The cast are the highest paid TV actors in the world

Unsurprisingly, considering the show’s success and how much said success is down to its cast, The Big Bang Theory’s stars are paid handsomely for their work.

[rtk_adunit_bottom]

Since 2017, Johnny Galecki, Jim Parsons, Simon Helberg, Kunal Nayyar and Kaley Cuoco have been making $1 million per episode.

Considering each season consists of 24 episodes, it should come as no surprise that the Big Bang principal cast members are as a result the highest paid TV actors in the world.

[rtk_adunit_top]

17. Animals have been named after the show

Not that you couldn’t already guess from the show’s many science-based cameos, but The Big Bang Theory is just as popular with scientists as is is with general audiences.

[rtk_adunit_middle]

This is evidenced by the fact that two different recently discovered species of animal have been named for the show, specifically after Sheldon’s favourite catchphrase.

The two creatures are the Bazinga rieki, a small jellyfish; and the Euglossa bazinga, a Brazilian orchid bee.

[rtk_adunit_bottom]

16. It’s the most successful sitcom since Friends

Though Big Bang peaked in season 9 with an average of more than 20 million viewers, the show still rakes in huge figures for a modern TV show.

[rtk_adunit_top]

Since 2012, the show has never dropped below an 18 million viewers per season average; for the past four seasons, it’s been the most-watched comedy on television.

This makes Big Bang the most successful sitcom since Friends, which never once dropped below a 20 million per season average.

[rtk_adunit_middle]

15. Kaley Cuoco and Johnny Galecki dated in real life (secretly)

After a number of seasons of will-they-won’t-they romance, Leonard and Penny finally tied the knot in season 9.

[rtk_adunit_bottom]

In real life, however, Leonard and Penny actors Johnny Galecki and Kaley Cuoco didn’t work out so well as a couple.

From 2007 to 2009, Galecki and Cuoco dated for real, though fans of the show didn’t find out until Cuoco admitted to it in an interview in 2010.

[rtk_adunit_top]

14. Soft Kitty is a real song

Soft Kitty, Sheldon’s favourite comfort song, isn’t a Big Bang invention, but has its origins in a folk song that dates back centuries.

[rtk_adunit_middle]

The show’s co-creator Bill Prady first heard the song from his daughter, who sang it at pre-school, though her teacher had first heard it while working in Australia.

This was the children’s song Warm Kitty, with words written by Edith Newlin in 1937, and itself based on an 18th century Polish lullaby called Wlazł kotek na płotek.

[rtk_adunit_bottom]

13. Kate Micucci could have played Amy

In season 6 – and, later, as a guest star, season 10 – Kate Micucci played Raj’s would-be girlfriend Lucy.

[rtk_adunit_top]

This wasn’t the first part on the show that the Garfunkel and Oates comedian had auditioned for, however.

Before she played Lucy, Micucci was in the running to play Amy Farrah Fowler, though Mayim Bialik just beat her to it.

[rtk_adunit_middle]

12. The cast learned to play instruments just for the show

The theremin might notoriously be one of the most difficult instruments to play, but Jim Parsons is one of the relatively few to have it mastered.

[rtk_adunit_bottom]

Parsons didn’t know how to play the electronic instrument before he joined The Big Bang Theory – he learned it specifically for the show.

Parsons wasn’t the only one: once it was decided that Amy Farrah Fowler would play the harp, Mayim Bialik set about learning the instrument from scratch.

[rtk_adunit_top]

11. The show was originally called Lenny, Penny and Kenny

Before Chuck Lorre and Bill Prady finally decided on The Big Bang Theory for their science-based sitcom, they considered a different title.

[rtk_adunit_middle]

The working title of the show at first was the perhaps less suitable Lenny, Penny and Kenny.

That’s right: while Penny and Leonard kept their names, Sheldon in this version of the show was named Kenny.

[rtk_adunit_bottom]

10. Howard’s mother was written out of the show after the actress who voiced her died

In season 8, Howard’s long-unseen mother, Debbie Wolowitz, dies suddenly off-screen (or, rather, off-soundtrack).

[rtk_adunit_top]

Mrs Wolowitz wasn’t written out of the show this way deliberately: the writing team felt they had no other choice after Carol Ann Susi, who had voiced Debbie since season 1, died on November 11, 2014.

Susi had died, aged 62, after a brief battle with cancer. She was last heard making a cameo as Mrs Wolowitz on the season 11 flashback episode The Bitcoin Entanglement.

[rtk_adunit_middle]

9. Macaulay Culkin turned down one of the lead roles

In 2018, Macaulay Culkin – yes, Home Alone and Richie Rich’s Macaulay Culkin – dropped a bombshell in an interview with Joe Rogan.

[rtk_adunit_bottom]

The former child actor revealed that he had been pursued not once, but three times to take one of the two leading roles on The Big Bang Theory back when Chuck Lorre was preparing the ill-fated first pilot.

According to Culkin, he was all “I’m cool, thanks” (and, the second time, “again, flattered, no”) about taking on the particular role – and we’re going to put good money on it having been Leonard.

[rtk_adunit_top]

8. Mary Cooper is played by a mother and daughter acting duo

Ever since season 1 of The Big Bang Theory, Sheldon’s intensely religious mother Mary has been played by Lauria Metcalf.

[rtk_adunit_middle]

Of course, when it came to casting Big Bang spin-off Young Sheldon, producers needed to go looking for another actress to play young Mary alongside Iain Armitage’s young Sheldon Cooper.

And who better to play a young Laurie Metcalf than Metcalf’s own daughter, Zoe Perry, who has starred as the younger Mary Cooper in 40 episodes of Young Sheldon to date.

[rtk_adunit_bottom]

7. The show has its own scientific adviser

Unusually for a TV sitcom, The Big Bang Theory has its own science consultant on staff.

[rtk_adunit_top]

David Saltzberg, a UCLA professor, has acted as technical adviser on the show since the pilot (and even the unaired pilot).

Saltzberg is kept around to make sure everything that the show’s scientist characters say and do is accurate.

[rtk_adunit_middle]

6. Melissa Rauch doesn’t actually speak like that

For ten years now, Melissa Rauch has played Howard’s squeaky-voiced partner, Bernadette, on The Big Bang Theory.

[rtk_adunit_bottom]

Considering the actress has never let up in a decade on the show, you’d be forgiven for thinking this is just how Rauch talks. Nuh-uh.

In real life, Rauch’s voice is much less high, as anyone who’s ever caught her in an interview will know.

Rauch actually took inspiration from her own mother: “Only without the Jersey! Tonally, it’s very similar”, Rauch revealed at a panel in 2013.

[rtk_adunit_top]

5. Leonard and Sheldon were named after a TV legend

Chuck Lorre didn’t come by the names Leonard and Sheldon by chance. The pair were, in fact, named after Sheldon Leonard, a legend of the entertainment industry.

[rtk_adunit_middle]

Starting out as an actor, with small roles in the likes of It’s A Wonderful Life and Guys and Dolls, Leonard later moved into producing for television.

It was here that Leonard developed a reputation, as the man behind such comedy classics as I Spy and The Dick Van Dyke Show – such a reputation that Chuck Lorre named two sitcom characters after him decades after his heyday.

[rtk_adunit_bottom]

4. The colour of Sheldon’s clothing changes according to his mood

The number 73 occasionally appearing there aside, Sheldon’s clothing is also significant for another reason.

[rtk_adunit_top]

Look closely, and you’ll see that the colour of Sheldon’s t-shirts change according to what his present mood is.

If Sheldon’s wearing red, he’ll likely be angry; yellow, fearful; green, courageous; and blue, hopeful.

[rtk_adunit_middle]

3. There’s a theory that the show is leading up to the apocalypse

Big Bang might have played out like your typical sitcom so far – but what if it’s heading somewhere much, much darker?

[rtk_adunit_bottom]

According to a recent analysis video from Cracked, The Big Bang Theory isn’t building to a predictable happy ending, but to the Big Crunch.

Basically, the Big Crunch is what scientists propose could eventually happen in our universe; the apocalyptic inverse of the Big Bang’s beginning.

Cracked proposes that The Big Bang Theory could end with one of the show’s scientist characters, distracted by the ‘sitcom bull***t’ of their lives, accidentally end life as we know it with a piece of high-tech CalTech equipment.

Seems unlikely, but that would make for one bold finale.

[rtk_adunit_top]

2. Bialik was referenced on the show two seasons before she joined

Though she’s been a main cast fixture for some time now, Mayim Bialik didn’t actually join Big Bang until season three.

[rtk_adunit_middle]

The actress – not the character – has been referenced on the show almost from the beginning, however.

In season one, as the gang discuss who might rival Sheldon in intelligence, Raj says: “You know who’s apparently very smart, is the girl who played TV’s Blossom. She got a PhD in neuroscience or something.”

‘TV’s Blossom’ was, of course, Mayim Bialik, who would join Big Bang in season three and go on to be Sheldon’s love interest and intellectual equal.

[rtk_adunit_bottom]

1. The set has only one set of stairs

For 12 seasons, Big Bang’s characters have been forced to take the stairs to their apartments, due to an eternally broken elevator.

[rtk_adunit_top]

This has resulted in numerous scenes of the characters walking up and down the stairway in conversation.

In reality, there is no ‘staircase’ – the set has just one set of stairs, with the set simply redressed for each different ‘floor’.

[rtk_adunit_end]